Control switch structure



April 18, 1933 M. E. HENNING 1,904,309

CONTROL SWITCH STRUCTURE Filed Jan. 27, 1 930 2 Sheets-Sheet 2 i @E11/wif -A Mako/nf.' [iN/fil?! J9/mm@ dlg/@raya pril 18, 1933.

M. E. HENNING 1,904,309

CONTROL SWITCH STRUCTURE Filed Jan. 27, 1930 2 Sheets-Sheet l 2720/00/40? ,gez/gf @fen/ga Patented Apr. 18, 1933 UNITED STA-TES PATENT OFFICE MALCOLM E. HENNING, OF DES MOINES, IOWA, ASSIGNOR TO PENN ELECTRIC SWITCH CO., OF DES MOINES, IOWA, A CORPORATION OF IOWA CONTROL SWITCH STRUCTURE Application filed January 27, 1930. Serial No. 423,677.

The object of my invention is to provide a.

Vcontrol switch structure which is simple, du-

rable and comparatively inexpensive to manufacture.

A further object is to provide a control switch structure having the operating parts condensed into a small casingl with certain features of construction which allow of such condensation.

Another object is to provide a' control switch structure adapted to be actuated by pressure or temperature with novel means of connecting the structure to a source of pressure, andan electric circuit to be controlled,

" such connections serving as a support for the casing of the control structure.

Another object is to provide in a structure of the character herein disclosed, a casing and a bellows therein Awith novel means of connecting the bellows with the casing for supporting one relative to the other.

Another object is to provide a struct-ure including control elements pivoted in a certain Way and operatively connected to each other witha connector of bail like construction.

Still a further object is to provide a switch structure having a magnet and a movable element, the movable element having a portion in the magnetic field and being acted upon by the magnet and a stop for the element with mechanism for adjusting the stop sothat the element will come to rest in a magnetic field of greater or less intensity as dex sired and thus the differential of operation of the movable element may be varied.

Another obj ect is to provide a novel means for modifying the actuation of the movable element for temporarily changing the range of operation of the device.

With these and other objects in view my invention consists in the construction, arrangement and combination of the various parts of my device, whereby the objects contemplated are attained, as hereinafter Vmore fully set forth, pointed out in my claims, and illustrated in the accompanying drawings, in which:

Figure l is a perspective view Aof my improved controlling device illustrating it con- Figure 3 is an enlarged sectional view on the line 3 3 of Figure 2.

Figures 4 and 5 are enlarged sectional Views on the lines 4-4 and 5-5 of Figure 2.

Figure 6 is a perspective view of a pair of controlling arms operatively connected together.

Figure 7 is a sectional view on the line 7--7 of Figure 5.

Figure 8 is an enlarged sectional view on the line 8-8 of Figure 2.

Figure 9 is a sectional view on the line 9 9 of Figure 8.

Figure l0 is n. view similar to a portion, of Figure 7 showing the parts in a diderent position.

Figure 11 is a similar view showing the parts in still another position.

0n the accompanying drawings I have used the reference character A to indicate generally a casing. The casing A is prefer.

nected with the fitting. Intermediate its ends the fitting 20 is screw threaded to receive a nut 26 whereby the fitting is supported relative to the casi g A.

The lower end of a bellows 28 is soldered or brazed to the upper end of the fitting 20 whereby the fitting forms a head therefor. The other end of the bellows 28 is closed by a head 30. A spring 32 is mounted Within the bellows 28 and extends from a socket in the top of the fitting 20 to a socket within the head 30. An insulating cap 34 rests on the head 30 and is provided with a peripheral A metallic point 36 is set in a socket in the upper side of the cap 34.

in a manner similar to the pin 42. An operaf tive connection is provided between the ar` mature arm 48 and the bellows arm 38. consisting of a bail 54. The bail 54 has an intermediate portion resting in a groove 56 in the bellows arm 38. Its ends are bent at right y angles to the intermediate portion and then parallel thereto, the lastmentioned portions extending through openings 58 in the ears 50 of the armature arm 48. The openings 58 are slightly spaced from the openings in the ears 50 through which the pivot pin 52 extends. 'f

The bellows 28 and the spring 32 therein are opposed by a sprin 60. One end of the spring 60 rests on a wasiller 62 having a point 64 coactin with the bellows arm 38 as best shown in igure 3. The other end of the spring 60 coacts with a rotatable adjusting washer 66 screw threadedly mounted on a stud 68. The stud 68has a reduced portion 70V formed beyond a shoulder 72. The reduced portion 70 extends into a socket 74 formed in the partition 10.

The free end of the armature arm 48 is located in the magnetic field of a magnet 76. The magnet 76 is glued, shellacked or otherwise xed in position within the casing A. A movable contact 78 is carried by the armature arm 48'and also movable relative to the armature arm. The contact 78 extends loosely through an opening in the armature arm and is connected with a leaf spring 80. The

contact 78 is adapted to coact with a contact 82 when the armature arm is in on position.

The contact 82 is carried by a movable platev The plate 84 is provided with a transverse slot 86. A n adjusting nut 88 has an eccentric ortion 90 within the slot 86 kas best shown 1n Figures 7, 10, and 11 of the drawings. The

' adjusting nut 88 is rotatably retained in position by means of a screw 92 extending into a contact blade 94. A spring 96 is interposed between the head of the screw 92 and the eccentric portion 90 of the adjusting nut 88. These parts provide for an electric circuit path from the contact plate 94 to the contact 82 through the screw 92, spring 96, nut 88 and plate 84 since these parts are made of metal. A second contact vbla-de 98 is mounted in the casing A and is connected by a flexible lead 100 with the armature arm-48.

As a means for changing the range of operation of the device I provide a leaf sprin 102 connected with the bellows arm 38. slot 104 is formed in the free end of the leaf spring 102. A flanged collar 106 having attened sides 108 as shown in Figure 9 is received in the slot 104. The interior of the collar 106 is coarsely screw threaded and coacts with similar threads on a shaft 110. The

the threads on the shaft 110 start coacts with the washer 124.

Assembly of my structure My device has been designed for ease in assembly. As a first step the bellows 28 is mounted in the casing A by pushing the fitting 20 through the opening 18 and applying the. nut 26'. The insulating cap 34 and the pin 36 can then be pushed into their proper positions. The arm assembly shown in Figure 6 Ais then placed in position and the plvot pins 42 and 52 inserted in the openings in the back of the casing A. The crossl bar 44 is placed in position and the screws 46 tightened. The assembly shown in Figure 8 is then arranged in its proper position and the screw 120 holds it assembled.

The contact blades 94 and 98 are inserted and the lead 100 connected to the blade 98 by a screw 99. The adjusting plate 84 and adjusting nut 88 are then placed in position and retained in such position by the spring 96 and screw 92. The assembly of spring 60 and washers 62 and 66 together with the stud 68 may then be slightlyv compressed and sliped into position whereupon its expansion will cause the reduced portions 70 and the shouldered portions 72 to rictionally engage the sides of the socket 74 and the face of the partition 10 respectively. The washer 66 may now be adjusted for the desired tension after which the cover 14 can be placed in position and secured to the casing A by the screw 16.

Us@ and operation tor 132.

y.The device can be used in many other installations and in the present one when the temperature increases, the bellows 28 will eX- pand for allowing the magnet 76 to draw the armature arm 48 to contact position. Upon this occurring the motor 132 will be energized for operating the refrigerating system and lowering the temperature in the refrigerator. When it has lowered sufficiently the bellows 28 will contract whereby the spring 60 will move the armature arm 48 to ofi position.

When it is desired to temporarily change the range of operation of the control structure the knob 118 may be adjusted for causing the spring 102 to oppose or assist the spring 60 so that the switch will turn oi and on at lower or higher temperatures.

In some installations it is desirable to have vthe differential of operation of the switch narrow and in others broad. Figures 2 and 7 illustrate a medium adjustment of the differential with a pointer 89 on the adjusting nut'88 halfway between a pair of stops 91 and 93 on the movable plate 84. When it is desired to increase the dierential of operation the armature arm 48 may be substantially closer to the magnet as shown in Figure 10 and farther away when it is desired to decrease the differential of operation as lshown in Figure 11. This is done by swinging the pointer 89 toward the stop 91 and the stop 93 as shown in Figures 10 and 11 respectively. This variation of the difierential of operation will in one adjustment make the switch operation to off and on positions over a scale of ten pounds'pressure for instance, while for another adjustment it will cut it down to two or three pounds for instance.

The entire casing A may be supported by the pipe 24 or by the contact blades 94 and 98 which may be plugged into an ordinary electric fitting having sockets to receive the blades. Such fittings are conveniently attached to a wall or other supporting surface whereby the casing may be supported. The entire casing being made of insulation prevents a shock being received from any part of the device. The cap 34 provides insulation between the metallic parts electrically connected with the armature arm 48 and the metal fitting 20. The hole above the screw 120 in the knob 118 after the screw has been tightened can be filled with sealing wax or other insulating' material 121.

Some changes may be made in the construction and arrangement of the parts of my device without departing from the real spirit and purpose of my invention, and it is my intention to cover by my claims, any modified forms of structure or use of mechanical equivalents, which may be reasonably included` within their scope.

I claim as my invention:

1. For use in afcontrol structure having a movable element and a magnet with the element having a portion located in the magnetic field of said magnet, a stop for said element and means for varying the differential of operation of the element comprising mechanism for changing the location of said stop with respect to said magnet, said mechanism including a cam and a spring retaining it against said magnet.

2. For use in a switch struct-ure having a movable element, a magnet with the element having a portion located in the magnetic iield of said magnet and a contact carriedby said element, a plate movable in its ownv plane, a second contact carried by said plate for coacting with the first Contact, said second contact serving as a stop for said ele- .ment whenl so coacting, said plate, upon movement, changing the locationof said second contact with respect to the magnet so that the element will stop in a different position, a screw through said plate and a` spring on said screw to retain said plate against said magnet.

3. For use in a controlling structure having a casing, a movable controlling element and amagnet pocket in said casing and a magnet therein with a portion of said element located in the magnetic field of said magnet. an adjustable stop for said element comprising a plate movable in its own plane and guided bythe sidesof said pocket, said plate having a slot therein and carrying a stop member for said element and a rotatable member having an eccentric for coaction with said slot.

4. For use in a controlling structure having a movable controlling element and a. magnet with a portion of said element located in the magnetic field of said magnet, an adjustable stop for said element comprising a plate having a slot therein and carrying a stop member, a pivot pin having a head, `a rotatable memberon said pin having an eccentric for coaction with said slot and a spring interposed between said headand said plate.

5. For use in a controlling structure having a movable controlling element and a magnet with a portion of said element lo- J cated in the magnetic field of said magnet, an

adjustable stop for said element having a slot, a rotatable eccentric coacting with said slot for moving said stop, said eccentric hav.- ing a shoulder coacting with said stop and means resiliently constraining said shoulder toward said stop.

6. For use in a controlling structure having a movable controlling element and a magnet with a portion of said element located in the magneticl field of said magnet, an adjustable stop for said element having a slot, a rotatable eccentric coac'ting therewith for moving said stop, a headed pin for said eccentric, said eccentric having a shoulder coacting With said stop and a spring between the head of said pin and said eccentric for causing said shoulder to resiliently engage said stop.`

7. For use in a controlling structure having a movable controlling element and a horse 23 shoe magnet with a portion of said element located in the magnetic field thereof, an adjustable stop for said element, a rotatable cam coacting therewith for moving said stop and means on said stop engaging between the 25 poles 01 said magnet to prevent rotation of said stop with said cam.

8. For use in a controlling structure having a movable. controlling element and a magnetwith a portion of said element located in the 39 magnetic field of said magnet, an adjustable stop for said element comprising a plate in Contact with said magnet, means for resiliently constraining said plate toward engagement with said magnet and a rotatable cam coact- J ing with said plate for moving the same.

9. For use in a controlling structure hav ing a movable controlling element and a magnet with a portion of said lelement located in the magnetic iield of said magnet, an ad- 49 just-able stop for said element comprising a plate in Contact with said magnet, a rotatable cam coacting with said plate for moving the same, a shoulder on said cam and means for constraining said shoulder to engage said plate and said plate to engage said magnet.

Des Moines, Iowa, November 25, 1929.

MALCOLM E. HENNNG. 

